The sport of shooting with a bow and arrow is known as archery. The bow and arrow were first used in prehistoric times for hunting and warfare. Firearms have long since replaced the bow and arrow for warfare and for most types of hunting. However, the bow and arrow continue to be used for target shooting and for some types of hunting. For example, hunting deer with the bow and arrow is popular in the United States.
The first arrows were wooden shafts with a sharpened tip. Man discovered that the effectiveness of the arrow was enhanced by fastening an enlarged arrowhead on the forward end of the arrow. Early arrowheads were made of stone or horn. Modern arrowheads are made of steel or other materials that are more durable, easier to manufacture, and sharper. Arrowheads with two to four blades about the arrow shaft axis are known as broadheads and are commonly used for hunting. Broadheads deliver a wide cutting edge to cause increased trauma to the internal organs and a more rapid death to the animal, which is considered more humane.
Two types of broadheads are used by hunters, those with fixed blades and those with movable blades. Broadheads with movable blades are commonly known as “mechanical” broadheads. Mechanical broadheads are more streamlined in flight (i.e., they create less drag/wind resistance) and contain blades that either deploy on contact or after contact. A mechanical broadhead is considered to deploy on contact if the forward-most part of the blade is exposed and the first contact of the blade with the target is made by this part. A mechanical broadhead is considered to deploy after contact if when the arrowhead enters the animal, the forward-most, knife portion of the blade penetrates to a certain depth prior to which an outwardly-extending wing (also known as a flange, lug, finger, spur, or lever) makes contact. When the wing makes contact, it is pushed back and the knife portion is deployed. The arrow then continues to travel forward with the knife portion deployed.
Mechanical broadheads with blades that deploy on contact are disclosed in Liechty II, U.S. Pat. No. 6,171,206, Jan. 9, 2001 and Grace et al., U.S. Pat. No. 8,449,416, May 28, 2013. Within this group of mechanical broadheads having blades that deploy upon contact are lesser desirable qualities including: the tendency to deflect on highly angled shots; loss of kinetic energy from cutting through bone, generally the ribs, by being fully deployed as they penetrate the exterior of the target animal (the hair, hide, and ribcage) before reaching the internal organs; and dulling of the cutting edge as a result of cutting through bone.
Mechanical broadheads with blades that deploy after contact are commonly known as delayed deployment broadheads. Delayed deployment pivoting blades are disclosed in Steinbacher, U.S. Pat. No. 2,568,417, Sep. 18, 1951; Rickey, U.S. Pat. No. 3,578,328, May 11, 1971; Bergmann et al., U.S. Pat. No. 4,166,619, Sep. 4, 1979; Palizzolo, U.S. Pat. No. Des. 279,813, Jul. 23, 1985; Stagg, U.S. Pat. No. 4,940,246, Jul. 10, 1990; Eddy, U.S. Pat. No. 5,178,398, Jan. 12, 1993; Forrest et al., U.S. Pat. No. 5,458,341, Oct. 17, 1995; Wohlfeil et al., U.S. Pat. No. 7,377,869, May 27, 2008; Ward, U.S. Pat. No. D583,897, Dec. 30, 2008; and Asherman, U.S. Pat. No. 8,435,144, May 7, 2013. The blades of these broadheads have elongated knife portions that are aligned parallel with the arrow axis during flight and shorter wing portions that are set back from the tip and that extend outwardly during flight. When the broadhead enters an animal to a depth that the wing portions make contact, the blades pivot. The pivoting movement causes the wing portions to move back to a position that is close to parallel with the arrow axis and the knife portions to move outwardly. This pivoting movement is highly desirable because it enables the shorter wing portions to extend during flight (thereby creating less drag) and the longer knife portions to deploy within the animal (thereby creating greater trauma).
The leading edge of the wing portion of the Eddy, Forrest et al., and Ward blade is sharpened whereas the leading edges of the wing portions of the other blades are dull. The wing portion of the Eddy, Forrest et al., and Ward blade is positioned forward of the pivot point of the blade. This position causes a spreading action upon deployment that creates unnecessary energy loss. Additionally, for the Eddy and Forrest et al. blade, the short straight sharp leading edge of the wing portion is at such an angle, nearly perpendicular to the axis, that it tends to inefficiently “blow through” the tough exterior (the hair, hide, and ribcage) rather than more efficiently cut through it. Furthermore, for the Ward blade, the leading edge of the wing portion is at such an angle that this blade will wedge between 2 ribs on entry causing the blade to cut through bone and lose energy.
Although these delayed deployment mechanical broadheads provide some improvement in conserving energy though the tough exterior of the target animal, there are unique qualities to each that are less than optimal. Accordingly, a demand exists for a mechanical broadhead with delayed deployment blades providing optimal energy conservation through the tough exterior of the target animal while utilizing efficient cutting techniques upon entry into the target animal.